Motor fuel and process of making same



Tatented Feb. 12, 1929.

NITED TATQES LESTER KIRSCHBRAUN, OF CHICAGO, ILLINQISL Moron FUEL ANDrnocnss or MAKING sans.

No Drawing. Application filed January 8, 1920, Serial No. 350,229.Renewed July 5, 1928.

This invention relates to improvements in motor fuels and process ofmaking same and refers more particularly to a motor fuel made from theso-called pressure distillate obtained from the cracking of hydrocarbonoils. It has been Well recognized in the art that hydrocarbons heavierthan gasoline, as for example, kerosine, gas oil and fuel oil, obtainedfrom the fractional distillation of crude petroleum, contained morepower for use in explosive engines than does gasoline. Two seriousdifiiculties have prevented the utilization of these heavier fuels foruse in internal combustion engines. First, the use of these heavy fuelstends to quickly carbonize the engine and secondly, the fuel must reacha relatively high temperature before it can be vaporized and explosiontake place. In a sense, one is really the corollary of the other for thereason that imperfect combustion takes place, resulting in theprecipitation of carbon. The addition of a substantial percentage ofgasoline helps but all at tempts to use these high boiling pointhydrocarbons in high grade internal combustion engines have failed.

lln the cracking of petroleum oils, the vapors are passed out of thestill to the condenser and thence to the receiver, where they arecondensed and collected, which are called pressure distillate. Thispressure distillate, in a sense, may be called synthetic crude. Incommercial operation of cracking hydrocarbon oils, it is now carried onin a very extensive scale, approximately 50% of the pressure distillateis gasoline or gasolinelike character While the remaining 50% are theheavier ends, consisting in portions of kerosene-like bodies, gas oilbodies, and fuel oil bodies and a small per cent of relatively heavyresidue. The cracking operation should, of course, be so regulated as toavoid as far as possible any of these relatively heavy residues ortarry-like bodies.

This pressure distillate as such is not used for motor fuels. The lightends or the gasoline content thereof are fractionally distilled OE andthen this fraction, which as stated ma be 50% of the pressuredistillate, is washed with dilute sulphuric acid, caustic soda and waterand then generally blended with a small amount of casinghead gasoline,before it is in a marketable condition. The remaining portion of. thepressure distillate is distilled down to coke and the distillateobtained from this second distillation put back into the pressure stillsto form part of the new charging stock and rerun as before. It is wellknown that the production of this pressure distillate necessitates theuse of considerable quantities of fuel, inasmuch as the crackingoperation takes place under relatively high pressure at hightemperatures.

Among the objects of the present invention are to provide a processwhich will make pressure distillate and then convert it into a motorfuel, preferably, as a single and continuous operation; to provide aprocess which obviates many of the steps necessary to convert pressuredistillate into marketable motor fuel; to provide a motor fuel whichwill have more power than ordinary gasoline but which, at the same time,will not carbonize the cylinders; to provide a motor fuel which can beeconomically made and in general to provide improvements of thecharacter referred to.

One manner of carrying out the process is as follows: Gas oil from theKansas field of say, 30 Baum gravity, is placed in a still and heated toan oil temperature of 750 with a pressure of say, 90 pounds, and thedistillation continued until one half of the initial gas oil charge hasbeen vaporized, passed out of the still and condensed and collected inthe receiver. By suitably subjecting the vapors in their passage fromthe still to the condenser, to dephlegmation or reflux condensingaction, the gravity of the pressure distillate may be regulated so as toproduce pressure distillate having a gravity of52 Baum. tillate, whilestill relatively hot, passes from the condenser to a second still whereit is fractionally distilled to vaporize all but the very heavy ends, i.e., those of a tarry-like nature. The distillate from this second orfractional distillation is then passed through a mechanical mixer whichmay be merely a kettle equipped with mechanical agitators so as tovigorously stir the material.

An emulsifying agent is added to the distillate in the agitator, as forexample, 1% of naphthenic acid. Water is then added, preferably in agradual manner, to the pressure distillate contained in the agitator soas to form an emulsion in which the pressure distillate forms thecontinuous phase and the water the dispersed phase. If the pressuredistillate is relatively clean -,,the second distillation, i. e., thefractional distillation, may be entirely omitted and the pres- Thispressure dis sure distillate passed directly from the first receiver tothe mixer or agitator where it is emulsified.

The pressure distillate, after being emulsified, as above stated, isready for use. It can be put in an internal combustion engine of a motorcar and used in exactly the same way as gasoline. Actual road tests withmotor fuel made from 50 degrees gravity pressure distillate obtained bythe cracking of as oil from the mid-continent field with a rich mixtureshowed a decided saving on fuel consumption without carbonizing thecylinders. This emulsion contained substantially 3% to 5% of water. Withthe same mixture in the same car, ordinary gasoline of commerce underlike conditions, produced only 10 to 12 miles to the gallon of gasoline.

One of the particular advantages of this motor fuel is the enormoussaving in refining costs over that now necessary to convert pressuredistillate into a marketable prod-' not. It is to be understood that thewater in the emulsified condition, is very finely and evenly distributedthroughout the hydrocarbon and it is the addition of this water thatpermits of the utilization of this crude pressure distillate as a motorfuel.

I claim as my invention:

1. A fuel for internal combustion engines, consisting of an emulsion ofpressure distillate obtained from the cracking of hydrocarbon oils,water and naphthenic acid as an emulsifying agent.

2. A fuel for internal combustion engines, consisting of an emulsion ofpressure distillate obtained from the cracking of hydro LESTERKIRSCHBRAUN.

